John thomas



UNITED STATES PATENT OFFICE.

IV- JOHN THOMAS, OF NEW YORK, N. Y.

FLO-Arme DRY-Dock.

Specncation forming part of Letters Patent No. 522, dated December 20,1837; Reissued May 1,

Tonfall whom it may concern Be it known that I, JOHN THOMAS, navalarchitect, of the city of New York, State of New York, have invented anew and Improved Floating ADry-Dock Applicable to the Repairing ofShips, Steamboat's, and other Vessels; andI do hereby declare that thefollowing is a full and exact description thereof.

My floating dry dock, when in use, is `to consist of such number ofseparate sections, or floating platforms as it may be necessary toconnect together for the patricular purpose for which it is to be used;that is to say, as many as may be required to sustain the weight of thevessel which is to be repaired.

The perspective View, Figure l, in the accompanying drawings exhibits avessel upon one of my dry docks, consisting of eight sections,orrcombined floating platforms. As each of these is precisely similar inits construction to the others with which it is to be connected, adescription of one, and of the mode of combining any number of themtogether, will serve for the whole. Each section consists essentially oftwo floats, or hollow rectangular trunks united permanently together bystrong timbers, and a floor, orA deck, and of twoV smaller trunks, orfloats, which are not permanent, but mov able, in a Way to be presentlydescribed; and which are employed for the purpose of giving additionalbuoyancy to the dock, to afford the means of regulating that buoyancy inany particular part where it may be required, and also to insurestability. The respective sections may, of course, be varied in theirdimensions, but the size which I shall assume for the purposeofdescription will furnish the proportions of the respective parts to eachother', and serve to aid the judgment in building them of other sizes.Fig. 2, represents a side view of one of the sections, which sectionsare sixty feet long, fro-m A to B, and are seventeen feet wide on thefloor. The framework on each side of the sections is similar to thatrepresented. C, is the upper, and D, the lower string pieces, which aresixty feet in length, sixteen inches deep, and eleven inches thick.These are joined to buttresses at each end, composed of timber of thesame size, with the string pieces and about eight feet long. The stringpieces and buttresses are well as the other parts of the frame work areto be strongly united together by dowels and screw-bolts. The buttressesare to be lined transversely, with four inch oak plank, or other strongtimber, as shown at E E; when these have been properly secured themiddle 1s to be wedged up so as to give a rise from a straight line, ofat least three inches. F, F, are two truss pieces, closely fitted andwell secured, as they are to sustain the thrust of the truss frame; theyare of the same size with the stringA pieces. The two sides of eachsection are connected together by beams N, N, N, crossing both above andbelow, from one to the other; and upon the upper beams the floor, ordeck, is laid; the beams are not only to be firmlyV bolted in theirplaces, but they are also to be connected by strong links of iron shownat t, It, it. The four links nearest to each end of the frame, I make ofinch and three quarters iron; the four next of inch and five eighths,and the four 4nearest the middle of inch and a half.` Theselinks have tosustain the whole lifting power applied, and consequently the wholeWeight of the vessel upon the dock. Great care must be taken, thereforeto wedge and chock them in the most perfect manner. The keel blocks O,O, rest upon the two center beams of the sections and at about thedistance of three feet within their sides.

The two floats, or hollow trunks, which are to give buoyancy to thesection, are.

placed one at each end; their sides are marked K, K, and the space whichthey occupy is represented by the dotted lines.

These fioats are each twenty six feet long,V

fourteen feet wide, with a medium depth of seven feet. They are madewater tight, and are strongly braced throughout. Fig. 3, gives aperspective view of one of these floats, the top planking being removed,to show the crossing timbers upon which it rests. It will be seen thatit is deeper at one end than at the other; this is for the purpose ofgiving to the top such an inclination as shall allow the air to escapereadily when the floats are being filled with water. Fig. 4e, is a viewof the top, and of one side of one of these trunks. By the aid of floatsH', of these trunks the pumps are placed, by which they are to beexhausted of their water, and they also receive the lower Vends of thetubes by which they are to be supplied with air.

L, L, L, Vare stanchions of 8 by 10 scantling, twenty five feet inlength from bott-om to top, braced at the ends as shown in the drawings,and having similar braces at their sides, one of which side braces isshown at Fig. 5. There are two other short stanchicns G, Gr, eleveninches apart `placed near each end of each section the stanchions beingconnected by a cross piece near their upper ends, leaving a space ofeleven inches bei tween them and the deck. Through the square openingthus formed, pieces of strong ti; ber, ten by live inches pass,toconnect the respective sections together; these tim# bers must be ofsuch length as to extend across one section, and to the middle ofthatadjoining it. The space t-hus occupied by the connecting timbers ismarked I.

The frames formed by thestanchions L,

L, L,Vand their appendages are to receive the smaller trunks or floats,intended to regulate the dock, and to insure its stability. One of thesefloats is shown at Fig. 6. They are each about seventeen feet long,eight feet wide, and three feet deep, each having a capacity of abouteleven tons. They are made air tight, without any opening into them,excepting it may be for freeing them of any accident-al leakage, as theyare never to be filled with water, but are constant-ly to retain theirflotant property. They are made to slide up and down within the framesformed by the stanchions L, L, L;

and they have 'a beam M, M, extending along their tops, which beam isnotched at each end to receive an iron bar, or tongue within the sideframes, which serves to guide them up and down; this bar or tongue hasholes through it to receive bolts, by which the floats are to beretained in their places, when raised, or forced down. The beams M, haveblocks m, m, on them, which serve as fulcra upon which levers may bemade to act, by which these floats may be depressed. It will be readilyperceived that the distance of these floats from the center of the dock,and their combined and separate buoyancy, will give a most efficientcontrol over the whole dock, and its load, under circumstances whichwould render all other float-ing docks insecure.

Fig. 7, shows an elevation of a part of the frame work, which supportsthe pumps by which the main trunks or floats are tol be exhausted oftheir water, and the tubes for the supply o-f air. These pumps may beVeach other.

worked in any convenient Way and have nothing peculiar in theirvconstruction or arrangement.

Should it be desired to extend the sections, so as to increase thelength of the dock without adding to the number of sections, this may beeffected by means of the connecting pieces passing through the spaces I,l; t-hese connecting pieces, and the decks also, are to have both holesthrough them, at a convenient distance apart, say two feet, which willallow of the respective sections being retained at any desired distancefrom When several sections are placed together, the width of thesections constitute the length of the` dock. y l

When this dock is to be used the vesselto be placed `upon' it must `havea depth of water below its keel equal, at least, to the height of thedock, from the bottom of it to the floor." To sink the dock, the maintrunks are allowed to fill with water, and ballast is then put upon thefloor suflicient to effect that object, and consequently allow thevessel to be placed upon it, and to be secured by shoring, in its properposition upon the middle of thedock, with its keel over the keel blocks.The pumping of the water out of the'inain trunks is then to becommenced, and as this goes on, and the dock rises, the smaller or endtrunks, are to be forced down, the larger floats ascending, and thesmaller descending simultaneously. It is of course, necessary to admitair int-o the main trunks as the water is pumped out, land this iseffected by allowing air tubes t-o pass down into them, in a manner soobvious as not to' require description;

Having thus fully described the construction of my floating dry dock,and t-he manner of using the same, I do hereby declare that I do notclaim as 0f my invention, either of the separate parts thereof, takenindividually; nor do I claim the application of floats, or trunks, fromwhich water is to be pumped for the purpose of lifting a vessel forrepairs, this having frequent-ly been done; but

lVhat I do claim, is- Y The making and using of the smaller, or

end trunks, or'floats, which are to be used in combination with the mainfloats, and are not to admit water, but are to be forced down as thedock, with its load rises, the whole combined and operatingsubstantially in the manner and for the purposes herein set forth.

J. THOMAS.

lVtnesses: Y

JOHN D. CLARK, CHRisToPHER CUMMINGS.

[FIRST PRINTED 1914,

